1. Field of the Invention
The present invention relates to an ink jet head and a method of manufacturing the ink jet head.
2. Description of the Related Art
In general, ink jet heads used for ink jet recording methods (liquid-ejecting recording methods) in which recording liquids are ejected to perform recording include ink passages, substrates including energy-generating elements for ejecting ink droplets placed in portions of the ink passages, and fine ink discharge ports (referred to as “orifices”) for ejecting the ink droplets in the ink passages with the energy generated from the energy-generating elements.
U.S. Pat. No. 6,143,190 discloses a method of forming a supply port for supplying ink to energy-generating elements by anisotropic etching. In this method, when a {100} plane of a silicon wafer with a {100} orientation is etched, etching proceeds such that a {111} plane which is inclined at an angle of 54.7 degrees to an etching start surface and which is tapered in the thickness direction is obtained. Among crystal planes of silicon, the {111} plane is unlikely to be etched with a solution.
On the other hand, in the case of setting the area of a front surface aperture of a supply port to a predetermined value, the area of a back surface aperture of the supply port is greater than the area of the front surface aperture of the supply port. Since the back surface of a substrate is a junction with a member for supporting the substrate, the back surface of the substrate needs to have a portion with an area sufficient to form a good bond therebetween.
A supply port can be formed in a substrate with a {100} orientation by a dry etching process so as to have a wall perpendicular to the substrate. However, it is difficult to form the supply port in a {111} plane of the substrate because the {111} plane thereof is resistant to etching.